Margo Shephard is the wife of Dr. Christian Shephard and the mother of Jack Shephard. When Christian went missing, Margo decided that it was Jack who should find his father as it was his fault in the first place after what he had done. She agreed with Jack’s father that Jack didn’t understand pressure. After much talk, she convinced her son to go to Australia and retrieve his father.

After six survivors were found on the island of Sumba, they were transferred by the U.S. Coast Guard to Honolulu. Margo Shephard was among the relatives of the survivors, together with parents of Hugo Reyes and parents of Sun Kwon.

She was also present at Christian's funerals, when Jack was speaking about his father. Little did she know, that another woman, that was a close person to her husband long ago, was also at the church at that moment.